ej.microui.display.transform

Class Rotate

java.lang.Object

ej.microui.display.transform.AbstractTransform

ej.microui.display.transform.Rotate

Direct Known Subclasses:

ImageRotation

public class Rotate
extends AbstractTransform

This class holds a context in order to perform a free rotation (0 to 360 degrees) on a renderable. The rotation is specified by the center and the angle. The reference point is the renderable top-left corner. The rotation point is relative to the current translation of the graphics context where the renderable will be drawn. The renderable anchor point is relative to the same translation and to the given alignment.

To rotate a renderable on itself, use the following lines:

int rx = x + renderable.getWidth() / 2;
int ry = y + renderable.getHeight() / 2;
rotation.setRotationCenter(rx, ry);
rotation.setAngle(78);
rotation.draw(gc, renderable, rx, ry, GraphicsContext.HCENTER | GraphicsContext.VCENTER);


To rotate a renderable around a circle, use the following lines:

rotation.setRotationCenter(rx, ry);
for (int i = 0; i < 360; i += 45) {
rotation.setAngle(i);
rotation.draw(gc, renderable, rx - diameter / 2, ry - diameter / 2,
GraphicsContext.TOP | GraphicsContext.LEFT);
}


Since:

2.4

Constructor Summary

Constructors

Constructor and Description
Rotate()

Method Summary

Modifier and Type	Method and Description
void	drawBilinear(GraphicsContext gc, Renderable renderable, int x, int y, int anchor) Draws the renderable applying the current rotation.
void	drawNearestNeighbor(GraphicsContext gc, Renderable renderable, int x, int y, int anchor) Draws the renderable applying the current rotation.
int	getAngle() Returns the current rotation angle.
int	getRotationX() Returns the current X coordinate.
int	getRotationY() Returns the current Y coordinate.
void	setAngle(int angle) Sets the new rotation angle.
void	setRotationCenter(int x, int y) Sets the new rotation center coordinates.

Methods inherited from class ej.microui.display.transform.AbstractTransform

getAlpha, getTranslateX, getTranslateY, isMirrored, resetAlpha, resetTranslate, setAlpha, setMirror, translate

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Rotate

public Rotate()

Method Detail

getAngle

public int getAngle()

Returns the current rotation angle.

Returns:

the current rotation angle.

setAngle

public void setAngle(int angle)

Sets the new rotation angle.

Parameters:

angle - the new rotation angle

setRotationCenter

public void setRotationCenter(int x,
                              int y)

Sets the new rotation center coordinates.

Parameters:

x - the x coordinate

y - the y coordinate

getRotationX

public int getRotationX()

Returns the current X coordinate.

Returns:

the current X coordinate.

getRotationY

public int getRotationY()

Returns the current Y coordinate.

Returns:

the current Y coordinate.

drawBilinear

public void drawBilinear(GraphicsContext gc,
                         Renderable renderable,
                         int x,
                         int y,
                         int anchor)

Draws the renderable applying the current rotation. This method uses the bilinear algorithm to render the renderable. This algorithm performs better rendering than nearest neighbor algorithm but it is slower to apply.

Parameters:

gc - the GraphicsContext where to render the drawing.

renderable - the Renderable to draw.

x - the x coordinate of the image reference anchor point

y - the y coordinate of the image reference anchor point

anchor - position of the image reference point around the anchor point

Throws:

java.lang.NullPointerException - if @{code image} or @{code gc} is @{code null}

java.lang.IllegalArgumentException - if anchor is not a valid value (BASELINE is illegal).

java.lang.UnsupportedOperationException - when the renderable cannot be rotated (not implemented)

See Also:

drawNearestNeighbor(GraphicsContext, Renderable, int, int, int)

drawNearestNeighbor

public void drawNearestNeighbor(GraphicsContext gc,
                                Renderable renderable,
                                int x,
                                int y,
                                int anchor)

Draws the renderable applying the current rotation. This method uses the nearest neighbor algorithm to render the conent. This algorithm is faster than bilinear algorithm but its rendering is more simple.

Parameters:

gc - the GraphicsContext where render the drawing.

renderable - the Renderable to draw.

x - the x coordinate of the image reference anchor point

y - the y coordinate of the image reference anchor point

anchor - position of the image reference point around the anchor point

Throws:

java.lang.NullPointerException - if @{code image} or @{code gc} is @{code null}

java.lang.IllegalArgumentException - if anchor is not a valid value (BASELINE is illegal).

java.lang.UnsupportedOperationException - when the renderable cannot be rotated (not implemented)

See Also:

drawBilinear(GraphicsContext, Renderable, int, int, int)